The long-term objective is to generate a physical map of human chromosome region 9q34 in yeast artificial chromosomes (YACs). This will be accomplished by screening several YAC libraries with DNA sequences previously mapped to 9q34 using hybridization and PCR based methods. Both total human and chromosome 9 specific YAC libraries are available and the DNA sequences to be used as probes include trapped exons and genetic markers. The physical mapping strategy is to nucleate contigs by identifying YACs containing the 9q34 single copy sequences and extend those contigs through YAC end recovery and chromosome walking. The strategy involves chromosome 9 specific YAC construction, screening and characterization, and cloning and characterization of chromosome 9q34 exons. The resultant physical map will be translated into STSs for efficient accessibility by the scientific community. The availability of this cloned physical map is expected to accelerate the cloning and characterization of several disease genes that have been mapped to human chromosome 9q34 such as Tuberous sclerosis and a form of Torsion dystonia.